Because our constraint-based approach is based on decision procedures and is modular, it can support more complex models of transducers:
(i) Symbolic Finite Transducers (s-FTs), which support large alphabets [1]}, and
(ii) FTs with lookahead, which can express functions that otherwise require non-determinism.
In addition, closure properties of transducers allow us to reduce repair problems for string transformations to our synthesis problem.
